Electric switch



Jan. 9, 1940. 54 BROWN 2,186,818

ELECTRIC SWITCH Filed Nov. 11, 19:57

Inventor: Geor e R. Brown,

Hus Attorney 7 Patented Jan. 9, 1940 UNITED STATES PATENT OFFICEELECTRIC SWITCH New York Application November 11, 1937, Serial No.173,954

10 Claims.

This invention relates to electric switches of the type employing liquidcontact circuit closers which are rotated to control the flow ofcurrent.

It is an object of the invention to provide an 3 improved constructionand arrangement of switches of this type in which the circuit closer maybe reversed in position to form a switch which is either normally openor normally closed.

Referring to the drawing Fig. l is an illus-' l tration of the switchapplied to a door jamb; Fig. 2 is a plan view of the switch with thehousing broken away; Fig. 3 is a cross-sectional view through the switchstructure; Fig. 4 is an exploded view of the clamping means for the 5connecting cable; Fig. 5 is an exploded view of the switch elements; andFigs. 6 to 9, inclusive, illustrate the liquid circuit contact closerand the various positions taken by the circuit closer during operationof the switch as a normally m open or a normally closed switch.

The switch comprises a cylindrical housing III which may be lined withan insulating shell II in order to insulate the switch elements from thehousing and the surrounding structure. The 25 housing is madein-cylindrical form for ease in mounting the switch. With an ordinaryrectangular switch housing it is necessary to mortise the mountingboard; with a cylindrical-housing, however, it is only necessary to borea hole N- and insertithe housing in order to mount the switch inoperative position thereby effecting a considerable saving in laborcosts. Within the housing III a base l2 of insulatingmaterial isprovided having a rearwardly extending projec-.

36 tion 13 which serves to separate the terminal angle strips l4 and'I5. In order to connect the terminal strips to the conducting wires,terminal screws I6 and I! are provided. The terminal wires may comprisepart of a BX cable 40 having conductors l8 and I8 and a protective armorl8". In order to clamp the armor, to the casing and thus prevent theconnections between the conductors and terminals from becoming loosened,opposed clamping members 19 and 20 45 are placed about the armorimmediately adjacent the housing 10. The clamping plates have prongs orprojections 2| and 22 extending within slots 23 and 24 formed uponopposite sides of the opening 25 placed in the end of the housing.

60 The clamping prongs grip the end of the housing as the clampingmembers are tightened about the armor by means of the screws 26 and 21threaded through openings l9 and 20' formed in the clamping members. Inorder to hold a liquid circuit closer in operative position, two contactmembers 28 and 29 are mounted upon the base 12 and are secured to theterminal strips l4 and I6, respectively, by means of rivets 36 and 3|.The contact member 28 is U-shaped, one end of the U being inserted in arecess 32 formed 5 in the base l2 where it is secured to the terminal l5by the rivet 3|. An insulating plate 33 overlies the recess to protectthe end of the contact member and is secured to the base by the rivet 30which connects the contact arm 29 to the terminal strip I4, the contactarm overlying the insulating plate. The contact member 29 and insulatingplate 33 are set into a recess-34 formed v upon the base, as best shownby Fig. 5. The contact members 28.and 29 are formed with projections 35and 36 which extend toward each other to engage and hold the liquidcircuit close 31.

The liquid circuit closer 31 comprises a pair of cup-shaped-metalterminals 38 and 39 which are separated by an insulating diaphragm 40which may be for-med of refractory material such as a ceramic material.In order to seal the edges of the terminals a glass bead 4| is formedbetween the metal terminals 38 and 33 and seals the junctions betweenthese terminals and the insulating diaphragm 40. Within the spaceenclosed by the terminals is a quantity of mercury 42 which forms theconductive medium between the two terminals. In the manufacture of the80 circuit closer the space enclosed by the terminals is evacuated andfilled with hydrogen gas at a pressure of one or more atmospheres, sothat the current-carrying capacity of the circuit closer is increased.The insulating diaphragm 40 is provided with an opening 43 shown byFigs. 6 to 9, inclusive, which is submerged in the mercury when thecircuit closer is in current-carrying position and which is moved to aposition above the mercury when the circuit closer is in open position.The terminals 38 and 39 of the circuit breaker are provided withdepressions 44 and 44' which are placed at the same angular position onthe circumferences of the terminals. For the purpose of mounting thecircuit closer on the contact members, the terminals are provided withdepressions 45 and 46 which are engaged by the projections 35 and 36formed on the contact members. In this manner the circuit closer ismounted for free pivotal movement about the contact members which at thesame time make contact with the terminal members of the circuit closerso that the merciu'y will close the circuit through the contact niembersas the opening in the diaphragm is inserted in the mercury. I

In order to operate the circuit closer, a cylinupon the projection 41' arectangular plunger 52 is provided with keys 53 which ride in thegrooves 50 and formed in the cup member 49. The plunger is guided andsupported upon bearing surfaces 54 formed in'a sleeve 55 which ismounted in recesses 56 formed on the front of the housing member. Theguiding surfaces 54 take the form of a rectangular opening formed in thesleeve 55 and are adapted to prevent the rectangular plunger 52 fromrotating as the keys 53 engage the grooves in the cup-shaped member, aswell as providing a support for the plunger. The plunger is held in anextended position by means of a spring 5'! which engages the rear of thecup member 49 at one end and bears against a washer 58 at the other end.An antifriction ball 59 is locked between the washer 58 and the end 60of the plunger to provide for free relative movement between anoperating means and the plunger. The keys 53 engage the inner edges 54of the bearing surfaces 54 and prevent the plunger from being expelledfrom the sleeve under the action of the spring 51. To hold the switchelements in assembled relationship, the sleeve 55 is provided withrearwardly extending arms 6| and 62 which coact with the beveled faces63 and 64 formed on the base member and which are provided at their endswith locking prongs 65 and 66 which engage the recesses 61 and 68 formedin the base member I2. The assembled switch structure is clamped to thehousing by a face plate 69 which retains the sleeve 55 in position inthe recesses 56 by means of the locking screw 10. In order to mount thehousing on a supporting wall or panel, grooves H are provided in theextension 12 formed on the housing member In. These grooves are adaptedto be engaged by supporting screws (not shown).

In assembled relationship the spring acts to hold the plunger inextended position. Depression of the plunger will cause rotation of thecylinder and circuit closer and compression of the spring. As the springis compressed it will exert a force on the rear of the cylinder causingthe projection 41' to press the contact 28 toward the contact 29 therebyinsuring a good electrical contact between the circuit closer and thecontact members as the switch is operated.

One use of the switch is as a door switch to control an electric circuitin response to the opening and closing of a door. This use isillustrated by Fig. 1, the switch being mounted in the door jamb J bymeans of the extensions 12 formed on the housing. The door D is providedwith an abutment plate 13 for cooperation with the plunger 52. Openingand closing of the door will cause the plunger 52 to be extended anddepressed, alternately, and thereby cause rotation of the liquid circuitcloser. The circuit closer is keyed to the cylinder 41 by means of thekey 48' and one of the depressions 44 and 44'.

By properly positioning the depressions 44 and 44' and the opening 3formed in the diaphragm. it is possible to reverse the liquid circuitcloser to provide a switch which is either normally open or normallyclosed.

Referring to Fig. 6 it will be seen that the depression 44 is formed ona linesubstantially 60 degrees to the left of the vertical, while theopening 43 is formed on a line substantially 60 degrees to the right ofthe vertical. The pitch of the spiral grooves 50 and 5| is so designedthat depression of the plunger will rotate the cylinder 4! and therebythe circuit closer through an angle of 120 degrees. If now the circuitcloser is inserted in the switch to take the position shown by Fig. 6and the plunger is in extended position, the switch will be normallyopen. It will be apparent that upon depression of the plunger thecircuit closer will move clockwise in the direction shown by the arrowthrough an angle of 120 degrees to a final position illustrated by Fig.'7. In this position the switch is closed with the opening 43 immersedin the mercury and the plunger is depressed completely within the cup49. In the event that it is desired to have a switch which is normallyclosed the circuit closer is removed from between the contacts and isreversed to a position illustrated by Fig. 8, so that the depression 44'on the opposite terminal will be engaged by the key 48 when the switchis in normal position with the plunger extended. It will be apparentthat if the switch is now operated by depression of the plunger thecircuit closer will be rotated clockwise in the directionshown by thearrow through an angle of 120, so that the circuit closer will take theposition shown by Fig. 9 with the opening in the diaphragm removed fromcontact with the mercury and the switch in open position. It will thusbe apparent that by providing the circuit closer with two depressions 44and 44' and by placing the diaphragm opening at an angle of 120 from thedepressions that a switch is devised which may be operated as a normallyopen or a normally closed switch by reversing the position of thecircuit closer.

What I claim as new and desire to secure by Letters Patent of the UnitedStates is:

1. In an electric switch, a liquid contact circuit closer, contact meanspivotally supporting said circuit closer, a cylinder keyed to saidcircuit closer, a cup having a spiral groove connected to said cylinderand a plunger having means cooperating with said grooves wherebyreciprocation of said plunger will cause rotation of said circuitcloser.

2. In an electric switch, a liquid circuit closer haying terminalportions, one of said terminal portions having a depression formedtherein, a rotatable member having a key engaging said depression,opposed contact means mounting said circuit closer for rotation, anelement having a spiral groove engaging said member, and a plungerhaving means engaging said groove whereby reciprocation of said plungercauses rotation of said circuit closer.

3., In an electric switch, a liquid circuit closer, opposed contactsmounting said circuit closer for rotation about its axis to open orclose a circuit. a cylindrical member keyed to said circuit closer, acup having a spiral groove inserted in said member, a plunger having aprojection inserted in said groove. and a spring between said cup andplunger.

4. In an electric switch, a liquid circuit closer, opposed contactmembers, said contact members having means pivotally mounting saidcircuit closer for rotation to open or close a circuit, a cylindricalmember keyed to said circuit closer, means having a spiral grooveinserted in said cylindrical member, and a plunger having a key coactingwith said groove whereby said circuit closer may be rotated uponreciprocation of said plunger.

5. In an electric switch, a liquid circuit closer having terminalportions, angularly aligned depressions formed in said terminals,contact means mounting said circuit closer for rotation to open or closea circuit, rotatable means having a key engaging one of saiddepressions, a reciprocating plunger, means to translate reciprocationof said plunger into rotation of said means to operate said circuitcloser, said circuit closer being reversible in said contacts with saidkey engaging the other of said depressions whereby said switch may beoperated as a normally open or anormally closed switch.

6. In an electric switch, a liquid circuit closer operable upon rotationto open or close a circuit, contacts pivotally mounting said circuitcloser, a rotatable member connected to said circuit closer, an elementhaving a spiral groove secured to said member and a plunger having meanscooperating with said groove whereby longitudinal movement of saidplunger causes rotation of said circuit closer, said circuit closerbeing connected to said member when said plunger is in normal positionso that the circuit through said contacts and circuit closer is in openposition, said circuit closer being adapted to be reversed in positionso that when saidplunger is in normal position the circuit through saidcontacts and circuit closer is in closed position.

7. In an electric switch, an elongated housing, a base positioned withinsaid housing, a. liquid circuit closer, opposed contacts supported bysaid base and mounting said circuit closer for rotation about its axisto open or close a circuit, a

rotatable member mounted within said housing in axial alinement withsaid circuit closer and being operatively connected therewith, areciprocable element mounted in said housing and movable in a directionparallel to the axis of said circuit closer and having a portionextending beyond the confines of said housing, and means interconnectingsaid element and member whereby movement of said element operates saidcircuit closer.

8. In an electric switch, a liquid circuit closer having terminalportions, angularly alined connecting means formed on said terminals,contact means mounting said circuit closer for rotation to open or closea circuit, rotatable means engaging one of said connecting means, areciprocating element, means to translate reciprocation of said elementinto rotation of said rotatable means to operate said circuit closer,said circuit closer be- 6, ing reversible in said contacts with saidrotatable means engaging the other of said connecting means whereby saidswitch may be operated as a normally open or a normally closed switch.

9. In an electric switch,a liquid circuit con- J troller, opposedcontacts mounting said circuit controller for rotation about its axis toopen or close a circuit, means provided with a spiral groove connectedto said circuit controller for rotation therewith and a plunger havingmeans I engaging said groove whereby reciprocation of said plungercauses rotation of said first-mentioned means and said circuitcontroller.

10. In an electric switch, a liquid circuit controller, opposed contactsmounting said circuit controller for rotation about its axis to open orclose a circuit, an element keyed to said circuit controller and beingprovided with a spiral groove and a plunger havinga projection engagingsaid groove whereby reciprocation of said plunger causes rotation ofsaid circuit controller.

GEORGE R. BROWN.

